package com.testproject.imageloadertest;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Collections;
import java.util.Map;
import java.util.Stack;
import java.util.WeakHashMap;

import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Matrix;
import android.widget.ImageView;

public class ImageLoader {
    
	private boolean isThumb=false;
	
    MemoryCache memoryCache=new MemoryCache();
    FileCache fileCache;
    private Map<ImageView, String> imageViews=Collections.synchronizedMap(new WeakHashMap<ImageView, String>());
    
    public ImageLoader(Context context){
        //Make the background thead low priority. This way it will not affect the UI performance
        photoLoaderThread.setPriority(Thread.NORM_PRIORITY-1);
        
        fileCache=new FileCache(context);
    }
    
    final int stub_id=  R.drawable.ic_launcher;
    public void DisplayImage(String url, Activity activity, ImageView imageView,boolean isThumb)
    {
    	this.isThumb = isThumb;
        imageViews.put(imageView, url);
        Bitmap bitmap=memoryCache.get(url);
        if(bitmap!=null)
            imageView.setImageBitmap(cropForThumb(bitmap));
        else
        {
            queuePhoto(url, activity, imageView);
            imageView.setImageResource(stub_id);
        }    
    }
        
    private void queuePhoto(String url, Activity activity, ImageView imageView)
    {
        //This ImageView may be used for other images before. So there may be some old tasks in the queue. We need to discard them. 
        photosQueue.Clean(imageView);
        PhotoToLoad p=new PhotoToLoad(url, imageView);
        synchronized(photosQueue.photosToLoad){
            photosQueue.photosToLoad.push(p);
            photosQueue.photosToLoad.notifyAll();
        }
        
        //start thread if it's not started yet
        if(photoLoaderThread.getState()==Thread.State.NEW)
            photoLoaderThread.start();
    }
    
    private Bitmap getBitmap(String url) throws Exception 
    {
        File f=fileCache.getFile(url);
        try {
	        //from SD cache
	        //Bitmap b = decodeFile(f);
	        Bitmap b = BitmapFactory.decodeStream(new FileInputStream(f));
	        if(b!=null)
	            return b;
	        
	        return downloadBitmap(url, f);
	        
        } catch (Exception ex){
           return downloadBitmap(url, f);
        }
    }

    //decodes image and scales it to reduce memory consumption
    /*
    private Bitmap decodeFile(File f){
        try {
            //decode image size
            BitmapFactory.Options o = new BitmapFactory.Options();
            o.inJustDecodeBounds = true;
            BitmapFactory.decodeStream(new FileInputStream(f),null,o);
            
            //Find the correct scale value. It should be the power of 2.
            final int REQUIRED_SIZE=70;
            int width_tmp=o.outWidth, height_tmp=o.outHeight;
            int scale=1;
            while(true){
                if(width_tmp/2<REQUIRED_SIZE || height_tmp/2<REQUIRED_SIZE)
                    break;
                width_tmp/=2;
                height_tmp/=2;
                scale*=2;
            }
            
            //decode with inSampleSize
            BitmapFactory.Options o2 = new BitmapFactory.Options();
            o2.inSampleSize=scale;
            return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
        } catch (FileNotFoundException e) {}
        return null;
    }
   */

    //Task for the queue
    private class PhotoToLoad
    {
        public String url;
        public ImageView imageView;
        public PhotoToLoad(String u, ImageView i){
            url=u; 
            imageView=i;
        }
    }
    
    PhotosQueue photosQueue=new PhotosQueue();
    
    public void stopThread()
    {
        photoLoaderThread.interrupt();
    }
    
    //stores list of photos to download
    class PhotosQueue
    {
        private Stack<PhotoToLoad> photosToLoad=new Stack<PhotoToLoad>();
        
        //removes all instances of this ImageView
        public void Clean(ImageView image)
        {
            for(int j=0 ;j<photosToLoad.size();){
                if(photosToLoad.get(j).imageView==image)
                    photosToLoad.remove(j);
                else
                    ++j;
            }
        }
    }
    
    class PhotosLoader extends Thread {
        public void run() {
            try {
                while(true)
                {
                    //thread waits until there are any images to load in the queue
                    if(photosQueue.photosToLoad.size()==0)
                        synchronized(photosQueue.photosToLoad){
                            photosQueue.photosToLoad.wait();
                        }
                    if(photosQueue.photosToLoad.size()!=0)
                    {
                        PhotoToLoad photoToLoad;
                        synchronized(photosQueue.photosToLoad){
                            photoToLoad=photosQueue.photosToLoad.pop();
                        }
                        //Bitmap bmp=getBitmap(photoToLoad.url);
                        Bitmap bmp=getBitmap(photoToLoad.url);
                        memoryCache.put(photoToLoad.url, bmp);
                        String tag=imageViews.get(photoToLoad.imageView);
                        if(tag!=null && tag.equals(photoToLoad.url)){
                            BitmapDisplayer bd=new BitmapDisplayer(bmp, photoToLoad.imageView);
                            Activity a=(Activity)photoToLoad.imageView.getContext();
                            a.runOnUiThread(bd);
                        }
                    }
                    if(Thread.interrupted())
                        break;
                }
            } catch (InterruptedException e) {
                //allow thread to exit
            } catch (Exception e){
            	
            }
        }
    }
    
    PhotosLoader photoLoaderThread=new PhotosLoader();
    
    //Used to display bitmap in the UI thread
    class BitmapDisplayer implements Runnable
    {
        Bitmap bitmap;
        ImageView imageView;
        public BitmapDisplayer(Bitmap b, ImageView i){bitmap=b;imageView=i;}
        public void run()
        {
            if(bitmap!=null)
                imageView.setImageBitmap(cropForThumb(bitmap));
            else
                imageView.setImageResource(stub_id);
        }
    }

    public void clearCache() {
        memoryCache.clear();
        fileCache.clear();
    }    
    
    //addition method by Jaime
    //crop image
    private Bitmap cropForThumb(Bitmap bitmapOrg){
    		
    	if(isThumb){
    		
    		
    		
    		//File file = new File()
    		//return decodeFile();
    		
    		int width = bitmapOrg.getWidth();
    	    int height = bitmapOrg.getHeight();
    	    int newWidth = 150;
    	    int newHeight = 150;

    	    // calculate the scale - in this case = 0.4f
    	    float scaleWidth = ((float) newWidth) / width;
    	    float scaleHeight = ((float) newHeight) / height;

    	    // createa matrix for the manipulation
    	    Matrix matrix = new Matrix();
    	    // resize the bit map
    	    matrix.postScale(scaleWidth/2, scaleHeight/2);
    	               
    	    // recreate the new Bitmap
    	    Bitmap resizedBitmap = Bitmap.createBitmap(bitmapOrg, 0, 0, 
    	                      width, height, matrix, true); 

    	    // make a Drawable from Bitmap to allow to set the BitMap 
    	    // to the ImageView, ImageButton or what ever
    	    //BitmapDrawable bmd = new BitmapDrawable(resizedBitmap);
    	    
    	    return resizedBitmap;
    	   
    	}else{
    		
    		return bitmapOrg;
    	}  
    }
    
    //download imag from web
    //@author jaime
    private Bitmap downloadBitmap(String url,File f)throws Exception{
    	
    	//from web
        Bitmap bitmap=null;
        URL imageUrl = new URL(url);
        HttpURLConnection conn = (HttpURLConnection)imageUrl.openConnection();
        conn.setConnectTimeout(30000);
        conn.setReadTimeout(30000);
        InputStream is=conn.getInputStream();
        OutputStream os = new FileOutputStream(f);
        Utils.CopyStream(is, os);
        os.close();
        //bitmap = decodeFile(f);
        bitmap = BitmapFactory.decodeStream(new FileInputStream(f));
        return bitmap;
    }
    
    public String returnPath(String url){
    	File f = fileCache.getFile(url);
    	return f.getAbsoluteFile().toString();
    }   
}
